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lassac|ttsetts  Socittg  for  t^e  Itomotion  of  ^griculte. 


THE 


PINE  MOTH  OF  NANTUCKET 


—  BETINIA    FRUSTRANA  — 


BY 


SAMUEL    H.    SCUDDER. 


BOSTON: 
A.    WILLIAMS   AND    COMPANY, 

1883. 


PUBLICATIONS 

OP  THE 

lassacltts^tts  Bm\^  for  t\t  ^xamim  at  ^griculturt 


THE 


PINE  MOTH  OF  NANTUCKET 

—  RETINIA    FRUSTRANA  — 


BY 


SAMUEL    H.    SCUDDER. 


BOSTON: 

A.    WILLIAMS   AND    COMPANY, 

283  Washington  Street. 

1883. 


Copyright,  18S2, 
By  Samuel  H.  Scudder. 


University  Press  : 
John  Wilson  and  Son,  Cambridge. 


THE    PINE    MOTH    OF    NANTUCKET. 


The  pines  on  the  island  of  Nantucket  (Pinus  rigida  Miller), 
set  out  some  twenty  or  thirty  years  ago,  are  fast  dying  in  large 
numbers  from  a  cause  hitherto  unknown.  A  great  many  have 
already  perished,  and  most  of  the  living  trees  look  sickly.  On 
the  "  Old  South  Road,"  from  Nantucket  to  Siasconset,  all  the 
trees  on  one  side  of  the  road  are  quite  dead,  or  fast  dying, 
while  upon  the  opposite  they  are  comparatively  healthy-look- 
ing, although  seriously  affected. 

On  Sept.  19,  1876,  I  went  to  this  spot  to  discover,  if  pos- 
sible, the  difficulty.  I  chose  first  a  dead  tree  on  Mr.  Crosby's 
land,  and  cut  it  down,  carefully  examining  the  trunk,  boughs, 
twigs,  bark,  and  roots ;  there  was  no  sign  of  the  work  of  any 
insect  sufficient  to  have  caused  the  death  of  the  tree,  —  none 
more  than  would  be  found  on  any  healthy  tree.  Next,  I  selected 
a  tree  that  was  nearly  dead,  the  uppermost  boughs  only  being 
in  leaf,  and  a  few  bunches  of  needles  appearing  at  different 
points  on  the  trunk.  I  cut  this  down,  and  examined  the  trunk, 
boughs,  bark,  and  roots  as  before,  with  negative  results ;  but 
when  I  searched  the  living  twigs  I  found,  always  at  the  extreme 
tips,  a  great  many  recently  dead  needles,  and  in  connection 
with  them  a  small  lepidopterous  insect,  and  in  such  numbers, 
both  here  and  on  hundreds  of  trees  afterwards  examined,  as 
to  leave  no  room  for  doubt  that  this  insect  is  the  sole  cause  of 
the  trouble.  The  only  other  insect  at  all  common  was  the 
larva  of  a  geometrid  moth,  which  had  nibbled  the  leaves  ex- 
tensively, but  not  enough  to  cause  serious  damage,  or  to  strike 


4  THE   PINE   MOTH    OF   NANTUCKE^T. 

at  all  at  the  life  of  the  tree ;  wherever  the  mark  of  the  blight 
was  found  upon  living  trees,  the  first-mentioned  insect  was 
present  in  vast  numbers,  and  very  nearly  all  the  damage  that 
had  been  inflicted  was  directly  traceable  to  its  devastations.  It 
is  a  minute  moth  of  the  family  of  Tortricidae,  referable  to  the 
genus  Retinia  (or  Coccyx  of  some  authors),  and  may  be  de- 
scribed as  follows : 

Retinia  frustrana  nov.  sp.    (Fig.  l.) 

Head  covered,  especially  above,  with  hoary  tipped,  smoky 
brown  scales,  giving  it  a  speckled  appearance ;  palpi  rather 
longer  than  the  head,  the  middle  joint  expanding  into  a  com- 
pressed, disk-like  plate,  half  as  large  as  the  head,  and  covered 
with  silvery  gray  scales,  which  are  dusky  toward  the  base,  the 
apical  joint  minute,  slender,  dusky  ;  antennae  equally  and  nar- 
rowly annulated  with  dark  brown  and  white.  Thorax  and 
patagia  of  much  the  same  color  as  the  summit  of  the  head, 
but  the  front  portion  of  each  tinged  with  pale  umber,  while  the 
hinder  portion  inclines  to  silvery  gray,  sometimes  to  a  decided 
degree. 

The  ground  color  of  the  front  wings  is  divided  between  a 
dull  yellowish  umber  and  a  deep  reddish  umber,  deepening  at 
points  to  a  bright  ferruginous.  The  former  prevails  in  the 
lower  half  of  the  outer  two-thirds  of  the  wing,  and  in  an  ob- 
lique subapical  band,  subparallel  to  the  outer  margin.  The 
latter  elsewhere,  but  becoming  subinfuscated  in  the  basal  third 
of  the  wing ;  the  brightest  parts  of  this  tint  are  found  in  a  large 
quadrate  patch  depending  from  the  middle  of  the  costa,  and 
an  oblique,  slightly  arcuate  streak,  directed  inward  from  the 
apex,  and  often  continued  a  little  out  of  line  over  the  lower 
half  of  the  wing,  breaking  the  lower  pale  patch  in  the  middle 
of  the  outer  half  of  the  wing.  Both  of  these  umber  tints  are 
overlaid  by  frequent  transverse,  perfect  or  broken  stripes  of 
lustrous  pearly  gray,  which,  with  the  diversity  of  the  ground 
color,  give  the  insect  a  very  variegated  appearance.  Nearly 
all  of  these  pearly  stripes  run  at  right  angles  to  the  costa,  and 
are  distributed  as  follows  :  The  most  important  and  persistent 
are  the  two  broadest,  which  divide  the  wing  into  nearly  equal 


THE  PINE   MOTH   OF  NANTUCKET.  6 

thirds,  the  outer  striking  the  inner  angle  of  the  wing,  where 
the  fringe  terminates ;  another,  nearly  as  constant,  crosses  the 
wing  a  little  beyond  the  middle,  is  slightly  bowed  outward, 
and  united  at  the  middle  with  the  outer  of  the  two  already 
mentioned,  forming  with  it  an  H,  with  one  straight  and  one 
bowed  leg ;  often,  on  the  left  wing,  it  more  nearly  resembles 
a  K  ;  besides  these  there  are  numerous,  often  partially  con- 
fluent, short  bars  or  stripes  on  the  upper  half  of  the  wing,  and, 
next  the  inner  margin,  very  brief  similar  bars,  increasing  in 
size  toward  the  base,  and  on  the  basal  third  forming  a  dull 
pearly  patch.  The  whole  of  the  basal  third  or  fourth  of  the 
wing  is  traversed  irregularly  by  transverse  pearly  lines,  often 
nearly  or  quite  confluent ;  and  in  some  individuals  the  whole 
basal  half  is  of  a  nearly  uniform  pearly  hue.  Many  of  these 
pearly  scales  appear  to  have  fuliginous  bases,  so  that  where 
the  patches  are  broadest,  the  color  is  usually  duller.  The 
outer  edge  of  the  wing  is  marked  by  scattered  black  scales, 
edged  within,  and  sometimes  without,  by  a  delicate  white  line ; 
and  the  fringe,  which  is  very  long,  especially  below,  is  pearly 
fuliginous,  often  deepening  apically  to  black,  and  with  all  the 
scales  minutely  white  tipped,  forming  transverse  lines  of  white 
upon  the  darker  ground. 

Hind  wings  very  pale  silvery  gray,  slightly  infuscated,  the 
fringe  infuscated  only  at  base,  outside  of  a  silvery  hue.  Legs 
silvery  gray,  the  tarsi  infuscated  above  at  the  base  of  all  the 
joints.  Abdomen  silvery  gray,  more  or  less  infuscated  above, 
or  sprinkled  with  brownish  fuscous  scales. 

Expanse  of  wings,  12-14  mm. ;  length  of  body,  4.75-5.75 
mm. ;  length  of  antennae,  3.5  mm.  Described  from  twenty 
specimens. 

There  seems  to  be  no  colorational  distinction  between  the 
male  and  the  female,  but  considerable  general  variation  both 
in  the  markings  and  in  the  tints  of  this  beautiful  but  destruc- 
tive insect.  Some  individuals  occur  in  which  the  deeper  col- 
ors are  intense,  while,  at  the  other  extreme,  the  pearly  scales 
have  spread  so  widely,  and  at  the  same  time  the  more  brilliant 
tints  have  become  so  subdued,  as  to  give  the  whole  insect  a 


6  THE    PINE   MOTH    OP   NANTUCKET. 

drab  appearance.  The  two  shades  of  umber,  also,  grade  into 
each  other  in  all  cases,  being  seldom  sharply  separated.  The 
markings  as  above  described  are  those  most  prevalent. 

The  larva  (fig.  4)  is  slender,  cylindrical,  slightly  depressed, 
of  a  pale  brown  color  above,  the  thoracic  segments  slightly 
darker,  with  a  faint  pale  mediodorsal  line,  which  broadens 
and  becomes  somewhat  yellowish  on  the  two  hinder  segments, 
on  the  last  occupying  nearly  the  whole  breadth  of  the  segment ; 
the  lower  part  of  the  sides  and  the  under  surface  are  dirty 
luteous.  The  head  varies  from  castaneous  to  pitchy  castane- 
ous,  is  broader  than  long,  obscurely  subcordate,  the  lateral 
hemispheres  being  tumid  above,  and  separated  b}'-  a  deep  and 
narrow  groove  ;  the  antennae  and  most  of  the  mouth  parts  are 
pale  luteous,  the  ocelli  black.  The  prothoracic  shield  is  of  the 
color  of  the  head,  transversely  obovate,  more  than  twice  as 
broad  as  long,  and  divided  by  a  pale  mediodorsal  stripe  ;  the 
hinder  margin  is  broadly  rounded,  the  front  margin  nearly 
straight,  and  the  lateral  margins  rounded  subangular,  posteri- 
orly melting  into  the  hind  margin.  The  anal  plate  is  scarcely 
darker  than  the  body,  small,  almost  semicircular,  but  less  than 
twice  as  broad  as  long,  and  slightly  tumid.  The  legs  are  of 
the  color  of  the  under  surface  of  the  body,  but  are  marked  with 
fuscous,  the  claws  reddish  ;  the  prolegs  are  also  fuscous,  and 
the  spiracles  edged  with  piceous.  The  body  is  uniformly,  but 
rather  sparsely,  clothed  with  microscopic  hairs,  scarcely  per- 
ceptible with  a  good  lens ;  and  besides  these  has  longer  and 
stouter,  but  still  delicate,  pale  hairs,  about  as  long  as  the  width 
of  the  body,  scattered  over  the  upper  surface,  arising,  one 
each,  from  minute  piceous  warts,  which  are  definitely  arranged 
on  both  sides  of  the  body  :  —  two  on  a  segment  in  a  dorso- 
pleural  row,  two  on  a  segment  in  a  ventro-pleural  row,  and  one 
on  a  segment  in  a  stigmatal  row.  There  are  similar  hairs 
scattered  more  irregularly  on  the  head  and  prothoracic  shield. 

Length,  13  mm. ;  breadth,  2  mm. 

The  chrysalis  (figs.  2,  2  a,  3,  3  a')  is  almost  uniformly  castane- 
ous, -with  wing-cases,  eye-covers,  antennae,  and  sometimes  some 


THE   PINE   MOTH    OF   NANTUCKET.  7 

of  the  liinder  edges  of  the  dorsal  scuta  of  the  abdomen  dusky. 
The  rostrate  prolongation  of  the  anterior  extremity  of  the  body 
(fig.  2)  is  bent  downward  at  a  slight  angle,  preserving  above 
the  curve  of  the  head,  pretty  strongly  and  uniformly  compressed, 
docked  apically,  triangular  as  viewed  laterally,  the  sides  hol- 
lowed, and  the  upper  surface  slightly  sulcate,  its  lateral  edges  a 
little  elevated  or  margined,  and  all  the  ridges  marked  with  black. 
The  pronotum  is  depressed  below  the  surface  of  the  head,  but 
bounded  posteriorly  by  a  sharp,  elevated,  backward  directed 
ridge,  higher  than  the  mesosternum.  All  the  abdominal  seg- 
ments behind  the  first  (fig.  2  a)  are  furnished  with  anterior  and 
posterior  dorsal  transverse  rows  of  minute,  sharp,  conical  tuber- 
cles or  points,  the  rows  nearly  equidistant,  those  of  the  movable 
segments  longer  than  the  others,  and  with  the  points  directed 
backward.  The  anterior  row  is  a  little  more  extended  than 
the  other,  and  is  formed  on  most  of  the  segments  of  larger  and 
more  distant  points  ;  in  advance  of  it,  at  the  line  to  which  the 
posterior  edge  of  the  preceding  segment  reaches,  is  a  shorter, 
delicate,  fine-edged  ridge  ;  and  a  similar  but  blunter  ridge 
continues  the  posterior  row  of  tubercles  around  the  body.  The 
very  tip  of  the  abdomen  (fig.  3  a),  which  is  truncated  and  blunt, 
bears  a  slight  coronet  of  points  similar  to  those  of  the  trans- 
verse rows. 

Length,  6  mm. ;  breadth,  1.25  mm.        ' 

The  eggs  seen  were  not  described. 

The  moth  appears  to  be  most  nearly  allied  to  the  European 
species  R.  duplana  Hiibn.  and  R.  sylvestrana  Curtis.  From 
specimens  of  the  former,  which  Professor  Zeller  was  kind 
enough  to  send  me  from  Germany,  it  differs  by  its  much 
smaller  size,  and  the  much  greater  irregularity  of  its  mark- 
ings, these  being  almost  always  clustered  into  four  or  five 
narrow,  equidistant,  transverse  belts  in  R.  duplana ;  a  tendency 
to  such  a  transverse  disposition  of  the  markings  exists  also  in 
R,  frustrana,  as  indicated  above,  but  mostly  confined  to  two 
comparatively  broad  belts.  From  R.  sylvestrana,  as  far  as  I 
can  judge  by  descriptions,  and  by  a  pair  of  English  specimens 


8  THE   PINE   MOTH    OF   NANTUCKET. 

sent  me  for  comparison  by  Professor  Fernald,  it  differs  by  its 
slightly  lesser  size,  the  color  of  the  head  and  palpi,  the  differ- 
ent disposition  of  the  markings  of  the  wing,  and  their  more 
brilliant  and  more  highly  variegated  tints  ;  in  R.  sylvestrana 
the  stripes  are  numerous,  very  slender,  and  tend  toward  con- 
fluence on  the  basal  half  of  the  wing,  giving  it  a  somewhat 
hoary  appearance,  in  which  respect  it  resembles  R.  duplana 
rather  than  R.  frustrana.  The  pupa  of  R.  frustrana  also  agrees 
with  that  of  R.  duplana,  and  is  distinguished  from  that  of  other 
Retiniae  (that  of  R.  sylvestrana  is  not  known)  in  the  rostrate 
prolongation  of  the  anterior  extremity  of  the  body  (see  figs.  2, 
3)  ;  the  close  affinity  of  R.  frustrana  to  the  two  above-men- 
tioned species  will  therefore  be  readily  granted. 

Although  I  have  not  been  able  to  follow  the  history  of  this 
insect  completely,  it  is  probably  double-brooded,  and  differs 
therein  from  the  European  species  which  it  most  resembles. 
R.  duplana  flies  in  Germany  once  a  year  only,  appearing  by  the 
end  of  March  or  the  beginning  of  April,  and  living  some  time 
into  May ;  the  larva  is  full  grown  by  the  end  of  June  or  the 
beginning  of  July,  when  it  changes  to  pupa,  and  in  this  con- 
dition continues  eight  months  in  the  year.  R.  sylvestrana  is 
said  to  appear  on  the  wing  in  England  in  June  and  July,  and 
has  a  similar  history  to  the  preceding,  excepting  in  its  later 
changes.  R.  frustrana  appears  in  Nantucket  between  these 
two  periods,  or  toward  the  end  of  April,i  and  flies  at  least 
during  May ;  probably  most  of  the  brood  has  emerged  by  the 
end  of  the  first  week  in  May.  Eggs  were  seen  in  one  instance 
May  15,  and  a  nearly  grown  larva  on  June  18.  Caterpil- 
lars may  be  found  fully  grown,  together  with  an  occasional 
chrysalid,  in  the  middle  of  July  ;  a  little  later  chrysalids  only 
can  be  found ;  and  again,  several  years  ago,  I  found  larvae  in 
great  abundance,  with  an  occasional  chrysalid,  about  the  mid- 

1  The  earliest  specimens  obtained  one  year  from  chj'salids  only  a  week  or 
two  in  confinement  in  a  warm  room  appeared  on  April  25th ;  the  earliest  of 
those  kept  the  same  year  in  a  cellar  appeared  May  8th.  A  single  living  moth, 
and  another  just  dying,  were  discovered  among  the  twigs  confined  in  a  box  as 
late  as  June  23d ;  how  long  they  had  been  out  of  chrysalis  there  were  no  means 
of  judging,  but  not  impossibly  several  weeks. 


THE   PINE    MOTH    OF   NANTUCKET.  9 

die  of  September.  Soon  after  that  all  change  to  chrysalids  ; 
for,  in  a  subsequent  year,  Mr.  S.  Henshavv,  who  visited  the 
island  September  17-19,  and  examined  the  trees  carefully, 
found  not  more  than  one  sixth  in  the  larval  state,  the  rest  in 
chrysalis.  In  all  probability,  then,  the  insect  is  double-brooded, 
flying  in  May  and  August,  and  wintering  in  chrysalis. 

Curious  as  this  difference  in  the  number  of  broods  between 
these  allied  species  in  Europe  and  America  may  seem,  it  is 
quite  in  accordance  with  what  occurs  in  other  Lepidoptera, 
where  analogous  species  are  found  upon  the  two  continents. 
I  have  not  studied  this  subject  in  the  nocturnal  Lepidoptera, 
but  among  butterflies  I  have  found  that  nearly  all  the  species 
which  are  identical,  or  very  closely  allied,  on  the  two  conti- 
nents have  at  least  one  brood  per  annum  more  in  North 
America  than  in  Europe.  Specifications  of  half  a  dozen  of 
these  cases  will  be  found  in  the  American  Naturalist,  Yol.  X. 
pp.  603, 601.  This  seems  to  be  largely  due  to  climatic  causes; 
and  it  naturally  follows  that,  when  an  injurious  insect  is  im- 
ported from  Europe  to  America,  its  ravages  here  are  likely  to 
surpass  anything  charged  to  it  in  its  proper  home,  —  a  point 
which  should  be  taken  into  account  by  students  of  economic 
entomology.^ 

Retinia,  the  genus  into  which  this  insect  falls,  is  represented 
in  Europe  by  no  less  than  eleven  species,  four  or  five  of  which 
are  common,  and  four  were  found  by  Ratzeburg  more  than 
forty  years  ago  doing  extensive  injury.^  They  all  feed  upon 
coniferous  trees,  perhaps  exclusively  upon  pines,  and  all  live 
upon  the  twigs ;  according  to  Ratzeburg  again,  all  are  single- 
brooded  with  a  single  exception  (R.  resinella),  where  a  gene- 
ration of  moths  appears  only  once  in  two  years.     When  I  first 

1  Mr.  C.  V.  Riley  (2d  Rep.  Entora.  Missouri)  asserts  that  destructive  insects 
introduced  from  America  into  Europe  make  no  headway  against  their  more 
"highly  developed"  allies  on  that  continent;  while  the  reverse  is  true  of  Eu- 
ropean pests  introduced  here,  "the  stronger  and  more  favorably  organized  spe- 
cies overpowering  and  starving  out  from  time  to  time  their  less  vigorous  and 
less  favorably  organized  competitors."  Unfortunately  he  gives  no  facts  to  sup- 
port this  highly  organized  theory. 

2  Three  of  these  four  have  now  been  found  on  the  Pacific  coast  of  the  United 
States. 


10  THE   PINE   MOTH    OF   NANTUCKET. 

observed  the  injury  at  Nantucket,  no  species  of  this  genus  had 
been  found  in  this  country ;  but  since  then  one  or  two  have 
been  found  in  this  section,  and  doing  a  considerable  amount  of 
injury  to  pines.^  Now  that  attention  has  been  drawn  to  them, 
no  doubt  other  notices  will  follow,  showing  that  we  have  to 
deal  with  a  whole  group  of  insects  specially  destructive  to 
pines  both  in  Europe  and  America ;  but  our  Nantucket  species 
proves  much  more  dangerous  than  the  European  R.  duplana 
and  R.  sylvestrana.^ 

The  different  species  of  this  genus  attack  the  trees  in  some- 
what different  methods,  but  they  all  agree  in  selecting  the  ten- 
derest  growing  shoots  for  their  ravages,  and  in  destroying  this 
sensitive  and  essential  part  by  boring  into  the  heart,  and  de- 
vouring the  sappiest  and  pulpiest  portion  at  the  base  of  the  nee- 
dles. Some,  like  a  species  recently  found  by  Mr.  Comstock  of 
the  Agricultural  Department  in  Washington  upon  Pinus  inops,^ 
live  a  part  of  the  time,  at  any  rate,  outside  of  the  twig,  for 
their  webs  may  be  seen  enclosing  the  base  of  the  bud  and  the 
surrounding  new  leaflets  ;  but  most  of  them,  like  R.  frustrana, 
live  entirely  within  the  shoot  from  the  moment  they  have  bored 
their  way  into  it,  and  undergo  therein  their  transformations. 

The  injury  done  by  R.  frustrana  to  the  pitch  pine  (Pinus 
rigida)  of  Nantucket  is  soon  detected  in  the  months  between 
May  and  September  by  noticing  the  dead  needles  at  the  very 

1  A  brief  notice  of  these  will  be  found  in  the  Appendix. 

2  Fernald's  Catalogue  of  Tortricidte  (1882)  gives  eight  species,  of  which,  how- 
ever, only  three,  including  K.  frustrana,  are  found  in  the  eastern  United  States. 
Of  the  five  found  on  the  Pacific  slope,  where  the  insect  fauna  has,  as  is  known,  a 
decidedly  European  aspect,  four  are  believed  to  be  identical  with  European  spe- 
cies, and  among  them  R.  duplana  and  R.  sylvestrana  occur. 

^  Since  this  was  written  Mr.  Comstock  has  published  his  notices  of  this  spe- 
cies (Eep.  U.  S.  Dept.  Agric,  1879,  pp.  236,  237,  pi.  5,  fig.  2),  which  he  consid- 
ers, on  Professor  Fernald's  authority,  to  be  the  same  as  that  here  described. 
There  can  be  no  doubt  of  their  very  close  relationship,  but  the  difference  in  the 
habits  of  the  larvae  in  the  two  localities,  botli  during  active  life  and  when  about 
to  undergo  metamorphosis,  would  be  very  singular  if  they  belong  to  the  same 
species.  The  specimens  carefully  studied  by  him,  also,  were  found  on  a  differ- 
ent species  of  pine.  I  have  made  no  comparison,  but  only  desire  here  to  call  the 
attention  of  those  who  may  hereafter  study  this  insect  to  this  fact.  For  further 
account  of  Mr.  Comstock's  observations,  see  the  close  of  this  paper. 


THE   PINE   MOTH    OP  NANTUCKET.  11 

tip  of  a  shoot  otherwise  of  a  fresh  green  color,  or  only  partially 
withered  near  the  dead  needles.  The  egg  must  be  laid,  as 
Ratzeburg  presumes  it  to  be  in  the  European  species,  between 
the  scales  of  the  bursting  bud,  from  whence  the  caterpillar  eats 
its  way  at  birth  into  the  very  heart  of  the  bud  near  the  extreme 
tip  ;  for  to  this  part  are  the  youngest  caterpillars  confined.  From 
this  point  the  growing  caterpillar  burrows  down  the  stem,  often 
for  from  four  to  six  centimeters,  and  thus  eats  the  very  life  out 
of  the  tree  ;  for  with  one  of  these  insects  at  nearly  every  bud, 
as  was  the  case  in  the  tree  I  cut  down,  and  in  the  accessible 
branches  of  many  others  examined  at  different  times,  the  tree 
must  speedily  perish.  As  the  caterpillar  works  downward,  one 
by  one  the  needles  find  their  supply  of  nourishment  cut  off, 
cease  their  further  growth,  lose  their  color,  and  wither,  —  the 
change  in  coloration  of  the  needles  showing  the  progress  of  the 
pest.  Fig.  6  shows  the  appearance  of  one  of  these  twigs  in 
which  the  caterpillar  has  bored  a  couple  of  centimeters.  Some 
of  the  terminal  needles,  as  may  be  seen  by  comparison  with 
fig.  5,  which  represents  an  unharmed  twig  of  the  same  tree, 
have  scarcely  had  a  chance  to  grow  at  all  before  being  robbed 
of  their  means  of  support,  and  have  turned  quite  yellow  ;  fur- 
ther down  the  stem,  where  also  they  are  wholly  withered,  they 
are  a  little  longer ;  still  further  they  are  longer  yet,  and  only 
partially  withered,  showing  more  recent  attack  ;  and  it  is  not 
until  the  wholly  green  and  fresh  needles  are  reached  that  they 
are  of  the  normal  length.  The  difference  between  an  uninjured 
twig  and  one  that  has  been  attacked  is  really  greater  than  ap- 
pears by  comparison  of  figs.  5  and  6  ;  for,  as  will  be  seen  on 
comparing  the  lower  normal  needles  of  each,  fig.  5  represents 
a  shoot  with  much  shorter  needles  than  fig.  6  would  normally 
have  had  throughout.  The  dome-shaped  contour  of  the  needle 
tips  in  the  healthy  shoots  is  well  represented  in  fig.  5,  and  the 
contrast  to  this  which  fig.  6  exhibits  is  very  marked,  and  tells 
the  story  of  the  damage  done.  The  specimen  represented  in 
fig.  6  was  chosen  rather  to  exhibit  this  point,  being  perhaps 
more  marked  than  usual.  Generally  the  whole  shoot  is  un- 
naturally swollen  and  disfigured  by  the  pitch  that  has  exuded 
from  the  injuries  caused  by  the  caterpillars,  as  may  be  seen  on 


12  THE   PINE   MOTH    OF   NANTUCKET. 

removing  the  needles  ;  tins  appears  in  fig.  9  of  the  plate,  to 
compare  with  which  a  healthy  shoot  with  the  needles  removed 
is  shown  in  fig.  7. 

As  the  insect  is  probably  double-brooded,  the  second  genera- 
tion has  to  attack  shoots  already  grown,  or  nearly  grown,  in 
which  case,  of  course,  the  change  of  contour  of  the  tip,  seen 
on  comparing  fig.  6  with  fig.  5,  does  not  ensue  ;  but  the  with- 
ered needles  are  all  of  nearly  the  full  length,  as  shown  in  fig.  8. 
In  this  figure  the  stem  has  been  cut  longitudinally,  to  show  the 
nature  and  extent  of  the  borings  of  the  caterpillar.  The  mid- 
dle of  the  stem  is  found  pierced  by  a  slender  cylindrical  pas- 
sage as  far  as  the  dead  needles  continue  ;  the  passage  is  lined 
with  silk  and  foul  with  excrement,  which  has  been  removed 
from  the  specimen  drawn.  As  far  as  the  boring  has  been  car- 
ried, the  withered  needles  fall  from  their  position  on  being 
touched,  having  nothing  but  a  shell  for  their  support. 

When  the  caterpillar  is  fully  grown  it  selects  a  place  within 
its  burrow  wherein  to  change  to  chrysalis ;  this  is  usually  at 
the  bottom  of  the  burrow,  but,  in  a  thick  shoot,  may  be  in  any 
part,  even  toward  the  tip,  where  it  can  push  a  lateral  passage 
obliquely  toward  the  base  of  one  of  the  needles.  Such  a  bur- 
row, vertical  in  this  case  and  not  oblique,  may  be  seen  in  fig. 
8  on  the  right  hand  of  the  regular  burrow  at  the  tip  of  the 
shoot.  Several  indeed  may  occupy  different  parts  of  the  same 
shoot ;  the  place  selected  is  slightly  enlarged  to  form  a  lon- 
gitudinal cell,  at  the  upper  or  outer  end  of  which  a  passage  is 
eaten  into  the  open  air,  which  may  generally  be  seen  with- 
out difficulty  from  the  outside,  if  looked  for  near  the  base  of 
the  needles,  while  the  nest  is  uninjured.  The  holes  left  by  the 
fallen  needles  must  not  be  taken  for  these  outlets ;  these  never 
seem  to  be  taken  advantage  of,  for  from  them  usually  exudes 
more  or  less  pitch,  closing  the  opening.  To  find  on  emergence 
from  chrysalis  that  the  means  of  egress  of  the  moth  was  gone 
would  prove  disastrous  to  its  life.  Half  through  the  eaten  open- 
ing the  chrysalis  forces  its  way  when  about  to  change  to  the 
imago. 

It  appears  then  that  this  insect,  by  selecting  for  its  food  in 
the  larval  state  the  point  where  the  greatest  amount  of  nour- 


THE   PINE   MOTH    OF   NANTUCKET.  13 

ishment  exists,  has  chosen  well  for  itself  but  ill  for  the  tree ; 
the  very  richness  of  the  nourishment  of  which  it  robs  the  tree 
tends  to  the  immense  abundance  of  the  insect,  which,  attack- 
ing the  tree  at  every  growing  point,  effectually  puts  an  end  to 
its  life.  The  nearly  dead  tree  I  cut  down  was  not  more  than 
seven  and  a  half  centimeters  in  diameter,  and  perhaps  four 
metres  high  ;  all  but  the  very  topmost  boughs  were  dead,  and 
here  the  foliage  was  extremely  scanty,  yet  I  could  certainly 
have  obtained  forty  or  fifty  caterpillars  and  chrysalids  from 
this  one  tree. 

At  first  sight,  certainly,  there  seems  nothing  to  prevent  this 
insect  from  continuing  its  ravages,  and  destroying  every  pine 
on  the  island.  The  only  encouragement  in  this  view  is,  that 
then,  for  want  of  pines,  the  moth  must  die.  In  the  hope  of 
finding  some  natural  means  of  its  destruction,  I  have  sought 
for  parasites  which  might  at  least  keep  it  in  check.  One  such 
I  found  the  first  day,  feeding  upon  a  larva ;  and  by  enclosing 
many  infested  twigs  in  a  tight  box  I  have  obtained  three  kinds 
of  hymenopterous  parasites,  —  one  a  species  of  Bracon  proper, 
another  a  minute  Perilampus,  both  apparently  undescribed. 
The  latter  is  far  the  more  abundant,  but  neither  appears  to  be 
sufficiently  common  for  us  to  place  much  reliance  upon  them, 
although  they  unquestionably  serve,  to  a  certain  extent,  to  re- 
duce the  numbers  of  the  moth.  The  only  possible  method  of 
combating  this  evil  is  directly  to  destroy  the  Retinia  in  some 
one  of  its  stages.  Bonfires  every  day  at  dusk  in  the  vicinity  of 
the  woods,  during  the  last  week  in  April  and  the  first  week  in 
May,  would  doubtless  destroy  great  numbers  of  moths  laden 
with  eggs,  and  would  give  healthy  employment  and  no  small 
delight  to  the  small  boys  of  the  island.  But  apparently  the 
only  effectual  means  of  destruction  is  one  indicated  by  the  his- 
tory of  the  insect,  but  which  would  be  useless  on  the  main 
land,  or  without  concerted  action  on  the  part  of  the  inhabitants 
of  the  island.  As  already  stated,  the  affected  are  speedily  dis- 
tinguished from  the  uninjured  shoots  soon  after  the  caterpillar 
has  commenced  its  work,  by  the  presence  of  dead  needles  at 
the  apex  of  an  otherwise  green  shoot ;  the  presence  of  the 


14  THE   PINE   MOTH   OF   NANTUCKET. 

enemy  is  thus  infallibly  disclosed.  The  month  of  June  then 
is  the  time  for  operation  ;  and  the  work  to  be  done  can  he  done 
once  for  all  hy  breaking  or  cutting  from  every  pine-tree  on  the 
island  evei'y  affected  shoot. 

To  be  of  any  radical  use  this  must  be  done  during  a  single 
year,  to  leave  none  for  propagation  ;  for  the  same  reason  it 
must  be  done  to  every  tree,  great  or  small,  from  the  topmost 
boughs  of  the  tallest  trees  to  seedlings  just  springing  from 
the  ground ;  every  scattered  tree  or  seedling  upon  the  island 
must  be  searched.  I  examined  one  isolated  tree  about  a  metre 
high,  growing  a  kilometer  or  thereabouts  from  the  woods  on 
the  south  shore,  and  it  was  thoroughly  infested.  To  leave  such 
a  tree  would  be  to  have  the  labor  and  expense  of  the  proposed 
assault  in  vain.  The  work  must  be  completed  within  the  month 
of  June,  since  it  is  at  this  time  that  the  caterpillar  is  only  partly 
grown  in  its  burrow,  and  will  infalHbly  die  if  the  shoot  is  re- 
moved from  the  tree  ;  its  sustenance  will  be  gone,  and  it  cannot 
crawl  about  sufficiently  to  find  and  enter  another  tree.  This  is 
not  a  part  of  its  accustomed  line  of  action,  and  it  could  not  re- 
cover from  so  rude  a  shock  as  robbery  of  its  home.  There  would 
be  no  absolute  need  of  burning  the  broken  shoots,  but  this  might 
be  done  where  there  is  any  danger  of  their  falling  near  seedlings, 
which  it  is  possible  the  wandering  outcasts  might  enter  ;  and  it 
should  certainly  be  done  if  the  operation  has  to  extend  into  July, 
when  the  caterpillar  might  be  ready  to  change  to  chrysalis,  which 
it  could  do  in  its  burrow  whether  the  shoot  were  attached  to  the 
tree  or  fallen  to  the  ground.  Since  some  more  advanced  cat- 
erpillars might  as  early  as  June  undergo  such  transformation, 
doubtless  the  most  thorough  way  would  be  to  have  the  work  fin- 
ished before  the  end  of  June,  and  to  burn  every  broken  shoot ; 
to  cut  off  any  suspected  shoot  rather  than  to  leave  one  affected, 
or  even  to  remove  every  growing  shoot.^     But  anything  less 

1  I  am  told  by  good  botanists  that  the  tree  would  probably  recover  from  this 
Caesarian  operation,  and  it  might  be  easier  and  more  rapid  than  to  select  the 
affected  shoots.  It  certainly  would  be  safer.  Dr.  G.  L.  Goodale  has  called  my 
attention  to  the  following  passage,  which  seems  to  him  to  indicate  that  the  tree 
would  survive.  "  The  pitch  pine,  says  Smith,  differs  from  other  trees  of  this 
family,  its  stump  throwing  up  sprouts  the  spring  after  the  stem  has  been  felled, 
but  these  do  not  attain  any  considerable  height.     The  fallen  trunk  throws  out 


THE    PINE   MOTH    OP   NANTUCKET.  15 

radical  than  the  means  here  suggested  would  be  wasted  labor. 
Leave  them  alone  and  the  pine  woods  of  Nantucket  are  doomed 
to  destruction ;  to  plant  new  trees  would  be  to  add  fuel  to 
flames.  There  is  no  possible  escape  but  in  some  radical  and 
concerted  action  such  as  is  here  suggested ;  and  this  is  possi- 
ble only  because  of  the  isolation  of  Nantucket,  and  the  com- 
paratively small  extent  of  its  little  forest.  Ten  men,  each 
armed  with  a  pair  of  hedge  shears,  and  ladders  of  some  sort, 
ought  to  accomplish  it  in  the  month.  Whether  it  will  "  pay" 
is  for  the  Nantucket  people  to  decide.  But  if  they  will  not  do 
it,  their  next  best  plan  is  to  cut  down  the  entire  forest,  sell  the 
wood,  and  burn  the  brush,  leaving  not  even  a  seedling  any- 
where ;  then  to  pasture  the  sheep  upon  the  spot  for  two  years, 
and  carefully  destroy  every  seedling  that  springs  up  outside 
the  fences  which  confine  the  sheep.  After  that  it  would  be 
safe  to  plant  again  by  seed. 

Will  the  good  people  of  Nantucket  take  all  this  trouble  to 
rid  themselves  of  this  pest  ?  It  seems  extremely  doubtful, 
especially  since  concerted  action  on  the  part  of  all  the  land- 
owners would  be  necessary.  Just  here  our  impotence,  under 
republican  institutions,  seems  to  be  manifest.  "  Any  single- 
minded  and  prolific  worm,"  President  Eliot  has  happily  said, 
"  is  more  than  a  match  for  man."  But  this  is  mainly  because 
we  fight  it  single-handed.  No  great  success  is  to  be  expected 
in  checking  the  ravages  of  insects  in  this  country  until  the 
people  are ,  far  better  and  more  generally  acquainted  than  at 
present  with  the  simplest  rudiments  of  the  history  of  insects. 
I  do  not  believe  that  five  per  cent  of  the  people  of  Massachu- 
setts above  the  age  of  twelve  years  can  correctly  state  the 

sprouts  in  the  succeeding  summer ;  and  the  bundles  of  leaves  of  both  are  re- 
markable for  issuing  from  the  axil  of  a  single  leaf,  in  the  same  manner  as  in  the 
young  plant."  — MicHAux,  iV.  Amer.  Si/lva,  Vol.  III.  pp.  89,  90,  note  (1853). 

Mr.  George  B.  Emerson  also  says  of  the  same  tree :  "  Its  stump  throws  up 
sprouts  the  spring  after  the  stem  has  been  felled.  These  continue  to  flourish, 
■with  apparent  vigor,  for  several  years  ;  but  I  have  never  seen  them  attain  any 
considerable  height.  The  fallen  trunk  itself  throws  out  sprouts  in  the  succeed- 
ing summer ;  and  the  bundles  of  leaves  of  both  are  remarkable  for  issuing  from 
the  axil  of  a  single  leaf,  in  the  same  manner  as  is  observed  in  the  young  plant." 
—  Emerson,  Trees  and  Shrubs  of  Mass.,  State  ed.,  p.  73.   Svo,  Boston,  1846. 


16  THE   PINE   MOTH    OF    NANTUCKET, 

general  features  of  transformations  in  insects,  or  know  tliat, 
practically  speaking,  all  their  growth  comes  by  feeding  in  the 
larval  stage.  Without  such  knowledge  one  has  not  the  means 
of  learning  how  to  prevent  the  ravages  of  an  insect  never  be- 
fore met  with,  but  each  specific  case  must  be  treated  hap- 
hazard. 

Good  results  would  also  flow  from  proper  legislative  action, 
but  such  action  seems  curiously  abhorrent  to  the  republican 
mind.  Why  our  people  should  not  protect  themselves  in  this 
particular,  as  well  as  the  more  paternal  governments  of  Europe 
guard  the  interests  of  their  agriculturists,  it  would  be  hard  to 
say  ;  but  it  is  probably  owing  to  our  not  being  awake  to  the 
real  extent  of  the  injuries  done  by  insects,  and  the  need  in 
resisting  them  of  concerted  action,  which  only  State  authority 
can  enforce.  An  enlightened  public  opinion  in  this  matter  is 
too  far  away.  In  towns  immediately  adjoining  Boston  one 
may  every  year  see  orchards  completely  overrun  by  caterpil- 
lars, while  adjoining  nurseries,  properly  cared  for,  are  exempt. 
Why  should  the  owner  of  the  neglected  plantation  be  allowed 
to  put  his  neighbor  to  the  additional  pains  and  cost  his  neglect 
has  caused  ?  If  he  will  not  care  for  his  trees,  he  should  at 
least  cut  them  down,  and  not  make  them  special  breeders  of 
pests.  By  act  of  legislature  such  a  man  should  be  required  to 
take  all  reasonable  pains  to  prevent  the  increase  of  the  insects 
which  damage  his  own  and  his  neighbor's  property,  and  pen- 
alties should  be  rigidly  enforced.  Such  legislation  should 
certainly  be  restricted  to  enemies  already  known .  to  be  very 
harmful,  and  to  such  as  bid  fair  to  become  generally  danger- 
ous. The  decision  of  what  should  be  included,  especially  in 
the  latter  class,  and  what  means  should  be  taken  to  prevent 
the  increase  and  spread  of  insect  pests,  ought  to  be  in  the 
hands  of  a  scientific  commission,  created  by  the  State,  com- 
posed of  persons  who  are  familiar  with  insects,  and  who  should 
protect  the  interests  of  the  agriculturist,  the  gardener,  and  the 
nurseryman, — just  as  the  fish  commissioners  protect  the  fish 
supply,  see  that  proper  laws  are  framed,  and  that  these  are 
duly  regarded  and  enforced. 

The  insect  here  considered  may  be  taken  as  an  example  of 


THE    PINE   MOTH    OF   NANTUCKET.  17 

the  necessity  of  such  laws  and  such  a  commission.  It  has  prac- 
tically destroyed  the  timber  of  Nantucket,  but  has  never  yet 
been  found  on  the  adjoining  main  land,  or  in  any  other  part  of 
the  State.  A  careful  examination  of  the  pitch  pines  at  Wood's 
HoU,  during  the  height  of  its  devastations  at  Nantucket, 
revealed  no  trace  whatever  of  this  insect's  operations.  Should 
it  once  gain  a  foothold  there,  as  it  probably  will,  there  is  no 
apparent  reason  why  it  should  not  extend  to  the  Penobscot,  or 
as  far  as  the  pitch  pine  flourishes.  The  landed  proprietors 
everywhere  in  Massachusetts  have  then  a  personal  interest  in 
preventing  the  advent  of  such  an  enemy,  and  may  rightly  com- 
pel the  people  of  Nantucket  to  take,  at  their  own  cost,  active 
measures  for  the  destruction  of  this  pest. 

The  time  will  certainly  come  when  the  people  of  Massachu- 
setts will  demand  some  such  legislative  action  as  is  here  indi- 
cated ;  the  sooner  it  is  reached  the  better  for  the  material 
welfare  of  the  Commonwealth. 

As  this  paper  was  written  three  years  ago,  I  have  added,  in 
an  Appendix,  an  account  of  what  has  since  appeared  in  print 
concerning  the  moths  of  this  genus  in  the  United  States,  as 
observed  by  Professor  J.  H.  Comstock. 

It  may  be  added,  in  conclusion,  that  there  is  another  boring 
larva,  evidently  belonging  to  the  same  family  of  Tortricidae, 
also  found  in  the  shoots  of  this  Nantucket  pine,  which,  on  ac- 
count of  its  greater  size,  would  do  far  more  damage  than  Re- 
tinia  frustrana  were  it  at  all  common.  I  have  not  succeeded 
in  raising  it,  and  have  never  seen  more  than  six  or  eight  speci- 
mens. It  too  has  its  insect  foe,  —  a  parasite  belonging  to  the 
genus  Campoplex,  one  of  the  Ichneumonidae. 


APPENDIX. 


In  the  Report  of  the  Entomologist  to  the  United  States  Depart- 
ment of  Agriculture  for  1879,  as  published  in  the  Report  of  the 
Department  for  the  same  year,  pp.  233-238,  pi.  5,  figs.  1,  2,  Pro- 
fessor J.  H.  Comstock  gives  an  account  and  descriptions  of  three 
species  of  Retiuia,  all  attacking  the  pitch  pine. 

The  first,  described  by  Professor  Fernald  as  Retinia  corastocki- 
ana,  was  found  in  the  a^  icinity  of  Ithaca,  N.  Y.,  boring  into  the  twigs 
and  small  branches,  and  causing  an  exudation  of  resin.  They  often 
cause  the  death  of  the  twig,  especially  when,  as  in  many  cases, 
more  than  one  larva  lives  in  a  single  twig;  but  the  j^rincipal  dam- 
age done  was  in  disfiguring  the  shape  of  the  tree  by  the  destruction 
of  the  terminal  shoots.  They  pass  the  winter  in  the  larval  state, 
and  there  are,  apparently,  two  broods  a  year. 

A  second  species,  Retinia  rigidana  Fernald,  was  found  in  the 
same  place,  and  on  the  same  tree  ;  but  no  account  is  given  of  its 
habits,  further  than  that  they  are  "similar"  to  those  of  the  next 
species,  and  that  the  larva  inhabits  terminal  shoots. 

As  the  third  species  is  considered  by  Professor  Fernald  to  be 
the  same  as  that  described  in  this  paper  (but  see  above,  p.  10, 
note),  I  append  the  account  entire.  A  twig,  the  moth,  larva,  and 
chrysalis  are  figured  in  the  Report,  pi.  5,  fig.  2. 

"  Infesting  the  new  growth  of  Pinus  in  ops  and  P.  rigida  (and 
perhaps  of  other  species)  spinning  a  delicate  web  around  the  termi- 
nal bud,  and  mining  both  the  twig  and. the  bases  of  the  leaves; 
one  or  several  small  yellowish  larvae,  which  transform  within  gray- 
ish cocoons,  either  in  their  burrows  or  fastened  to  the  twigs,  and 
become  small  copper-colored  moths,  with  wing  expanse  of  12  mm. 
(.47  inch)." 


APPENDIX.  19 

"  Aoout  the  middle  of  May,  1879,  the  scrub-pines  (Pinus  inops) 
in  Virginia,  near  Washington,  were  found  to  be  greatly  injured 
by  small  lepidopterous  larvae.  On  many  trees  there  was  scarcely 
a  new  shoot  to  be  found  which  was  not  infested  at  its  tip  by  fi-ora 
one  to  four  yellowish  black-headed  caterpillars.  They  were  so 
completely  concealed  while  at  work  that  their  presence  Avould 
scarcely  be  noticed,  and  the  effect  of  their  work  was  hardly  visible 
until  the  twig  was  almost  completely  destroyed.  Upon  close  exam- 
ination a  delicate  web  was  seen  inclosing  the  base  of  the  bud  and 
the  surrounding  new  leaflets,  resembling  much  the  nest  of  a  small 
spider.  When  this  web  was  removed,  one  or  several  little  yellow 
caterpillars  were  seen  either  retreating  into  a  mine  in  the  bud  or 
into  the  bases  of  the  leaves,  which  were  also  mined,  or,  not  infre- 
quently, they  dropped  from  the  twig,  suspending  themselves  by  a 
silken  thread.  The  bud  was  often  so  hollowed  that  it  dropped  to 
pieces  almost  at  a  touch. 

"  At  the  time  when  they  were  first  noticed  larvae  of>  almost  all 
sizes  were  to  be  found.  Some  wei^e  apparently  almost  full-grown, 
while  others  had  evidently  not  been  long  hatched.  The  nearly 
full-grown  specimens  measured  8  mm.  (.31  inch)  in  length.  The 
first  pupae  were  obtained  early  in  June.  Most  of  the  larvae  trans- 
formed within  the  burrows  which  they  had  made,  first  spinning 
more  or  less  of  a  silken  envelope  about  themselves.  Others,  how- 
ever, issued  from  their  mines,  and  spun  rather  tough  grayish 
cocoons  between  the  leaves.  The  pupae  were  short,  stout,  and 
brown  in  color,  with  each  segment  furnished  dorsally  with  two 
serrated  lines,  one  consisting  of  large,  and  one  of  fine  teeth. 

"  The  first  moths  issued  June  13,  the  pupae  having  previously 
worked  their  way,  by  means  of  the  spines  just  mentioned,  into 
such  positions  that  they  could  give  forth  the  moths  without  injury 
to  the  latter,  and  a  few  weeks  later  almost  every  shoot  had  one 
or  more  of  the  empty  pupa  skins  protruding  from  it.  Speci- 
mens of  the  moths  were  sent  to  Professor  Fernald,  who  deter- 
mined them  as  identical  with  Mr.  Scudder's  manuscript  species, 
Retinia  frustrana.  In  August  Mr.  Sciulder  gave  a  short  account 
of  this  insect  before  the  entomological  section  of  the  American 
Association  for  the  Advancement  of  Science,  at  Saratoga.  He 
had  found  it  in  such  numbers  upon  the  island  of  Nantucket  in  the 
young  trees  of  Pinus  rigida,  planted  there  some  years  ago  to  re- 
pair the  damage  done  by  burning  during  the  war  of  1812,  as  to 
seriously  threaten  the  success  of  the  experiment.     Mr.  Scudder 


20  APPENDIX. 

intends  publishing  an  account  of  the  workings  of  the  insect  in 
that  locality  very  shortly. 

"  In  the  latter  j^art  of  July  specimens  of  the  twigs  of  Pinus 
rigida  were  received  from  Mr.  S.  H.  Gage,  of  Ithaca,  which  had 
evidently  been  infested  by  the  same  insect,  although  no  living  in- 
habitants were  to  be  found.  In  Sej^tember  other  specimens  were 
received  from  the  same  gentleman,  and  this  time  two  pupae  and 
one  larva  Avere  found.  According  to  Mr.  Gage,  the  insect  is  not 
very  common  in  that  locality. 

"  In  the  latter  part  of  August,  individuals  of  the  second  brood 
were  very  abundant  in  the  scrub-pine  in  the  vicinity  of  "Washing- 
ton. As  before,  they  were  found  in  almost  every  stage  of  growth, 
and  the  difference  was  even  moi-e  marked.  In  one  instance  five 
larvae  of  greatly  differing  sizes  were  found  in  one  shoot.  The 
smaller  ones  were  boring  into  the  bases  of  the  leaves,  and  the 
larger  ones  into  the  twig  proper.  The  largest  of  the  five  had  made 
quite  a  long  channel  from  the  tip  of  the  bud  down  into  the  heart 
of  the  twig.  Pupae  were  also  found  at  this  time,  which  did  not 
give  forth  the  moth  till  late  in  the  winter. 

"  The  usual  mode  of  hibernation  is  in  the  pupa  state.  A  thor- 
ough search  in  January  in  the  field  showed  only  pupae.  The 
pupae  collected  in  August  and  September  did  not  begin  to  give 
forth  the  moths  in  the  breeding  cages  before  early  January,  though 
this  was  continued  at  intervals  through  January,  February,  and 
March,  and  was  greatly  hastened  without  doubt  by  the  heat  of  the 
room.  On  February  15,  however,  a  few  twigs  were  collected, 
from  one  of  which,  on  February  28,  a  full-grown  larva  had  emerged, 
and  was  found  crawling  about  the  cage.  This  would  seem  to  in- 
dicate occasional  larval  hibernation. 

"  As  to  remedies,  the  only  one  which  I  can  suggest  at  present 
is  that  involving  the  somewhat  arduous  task  of  picking  off  the 
infested  twigs  in  early  winter  and  burning  them.  Whether  the 
salvation  of  the  trees  will  be  worth  this  labor  in  greatly  infested 
regions  will  depend  entirely  upon  their  value  to  those  interested. 

"  As  Mr.  Scudder  has  prepared  descriptions  of  all  stages,  we 
will  not  trespass  upon  his  ground  by  appending  further  descrip- 
tions than  we  have  already  given.  Our  figure  will  assist  in  the 
recognition  of  the  species." 


ANALYSIS. 

PAGE 

Outward  aspect  of  affected  trees 3 

Description  of  moth 4 

Description  of  caterpillar 6 

Description  of  chrysalis 6 

Resemblance  of  the  moth  to  other  species  of  Retinia 7 

Life  history  of  Retinia  frustrana 8 

Its  appearance  on  the  wing  oftener  in  America  than  in  the  allied  species  of 

Europe  is  in  keeping  with  what  is  seen  in  other  insects 9 

Habits  of  the  European  species  of  Retinia 9 

Description  of  the  injuries  caused  by  Retinia  frustrana 10 

Its  mode  of  hibernation 12 

Its  parasites,  and  various  modes  of  attacking  it 13 

The  only  effective  remedy  against  the  ravages  of  the  insect  to  destroy  its 

means  of  subsistence,  and  after  proper  delay  plant  again 14 

Legislative  enactments  for  the  protection  of  agricultural  and  arboricultural 

interests 16 

Appendix  :  Professor  Comstock's  account  of  our  native  species  of  Retinia  .  18 

Explanation  of  the  plate 22 


EXPLANATION   OF   THE   PLATE. 


[The  original  drawings,  both  plain  and  colored,  were  made  by  Mr.  J.  Henry- 
Blake  of  Cambridge.  The  reproduction  by  chromolithography  is  the  work  of 
Messrs.  Thos.  Sinclair  and  Sons,  of  Philadelphia.] 


Retinia  frustrana  and  Pinus  rigida. 

Fig.  1.     The  moth,  enlarged  three  diameters. 

"  2.  Side  view  of  clirysalis,  enlarged  three  diameters.  2  a.  One  of  the  ab- 
dominal joints,  enlarged  nine  diameters,  to  show  the  rows  of  spines 
and  ridges. 

"  3.  Front  view  of  chrysalis,  enlarged  three  diameters.  8  a.  The  terminal 
joints  of  the  abdomen,  enlarged  nine  diameters,  to  show  the  arrange- 
ment of  spines  and  hairs  at  the  tip  of  the  body. 

"    4.     Full-grown  caterpillar,  enlarged  four  diameters. 

"    5.     Terminal  shoot  of  the  pine  in  an  uninjured,  natural  condition. 

"  6.  Terminal  shoot  which  has  been  attacked  by  the  insect  when  the  apical 
leaves  were  only  partly  grown  ;  away  from  the  tip  the  needles  have 
nearly  or  quite  attained  their  full  growth  before  the  mining  opera- 
tions of  the  caterpillar  had  sapped  their  supply  of  nourishment. 

"  7.  Terminal  shoots  in  a  healthy  condition,  stripped  of  its  needles,  to  con- 
trast with  fig.  9. 

"  8.  An  infested  shoot  cut  open  to  lay  bare  the  mine  of  the  caterpillar  in  its 
latest  stage ;  the  refuse  which  nearly  fills  it  has  been  removed.  The 
length  of  the  terminal  needles  shows  this  shoot  to  have  been  well 
advanced  in  its  growth  before  it  was  attacked. 

"  9.  A  shoot  similar  to  that  represented  in  fig.  7,  but  which  has  been  dis- 
torted by  the  attacks  of  the  insect. 


J  Henry  Blake, ad  r.ai.  1'  SincLair&aon.l'ith  Phlla. 

THE  PINE -MOTH  OF  .VWrrCKET  . 


